Preheater for aircraft



Sept. 8, 1942. 1 T K|NG 2,295,177v

PREHEATER FOR AIRCRAFT Filed July 29, 1940 2 Sheets-Sheet 1 Sept. 8; 1942. J. T. KING PREHATER FOR AIRCRAFT vFiled July 2 9.` 1940 2 sheets-sheet 2 Patented Sept. 8, 1942 UNITED STAT James rnEnE'A'rEn Fon Amcnm T. King, Los Angeles, Calif., assigner to Leo M. Harvey, vLos Angeles, Calif.

Es PATENT OFFICE Appueation' .Iniy z9,194b,'seria1 No. 348,183

zolaims. (onzas-19) This invention rentes to heating devices rnd relates more particularly to heaters for preheating aircraft engines, nacelles, cabin compartments, etc. A general object of this invention is to provide a practical safe andeiiicient aircraft preheater of vthe character mentioned.

burner controls, heater, stack, etc., andrprovided v with wheels and skids to be quickly moved from.

o place to place.

Uli

The internal combustion engines'of aircraft are not suitable for use until they have been heated to eflicient operating temperatures. tomary to warm up an aircraft engine by allowing it to run idle for a considerableperiod and It is cusin some cases the engine is heated or partially heated with'the flame f a blow torch. Warming up an aircraft engine by allowing it to .run idle for a substantial time with the plane grounded is time consuming and expensive, requiring a considerable amount of engine fuel. Further, the l operation of the aircraft engine when cold sub'- jects the engine to excessive wear, the cold lubricants being ineffective during the warming up operation.

Another object of this invention is to provide a portable heater operable to quickly and effectively warm or preheat the engine of'an aircraft for immediate eflicient operation.

Another object of this invention is to provide A a heater of the character mentioned having a shroud adapted to be'arranged about the engine cowl and an eicient heater means delivering heated air to the shroud to warmthe entire engine and adjacent parts.

Another object of this .invention'is to provide an aircraft heater of the character mentioned embodying an adjustable, insulated stack leading to the shroud, adapting the device for the immediate preheating of .engines of different sizes,

Another object of this invention is to provide an aircraft preheater of the character referred to in which the stack may be manipulated or arranged to discharge into the nacelles, cabin compartment, or otherpart of the aircraft to warm the lubricant tanks, lubricant lines, etc.

and to make the cabin readyfor occupancy and,

if desired, may be conditioned and employed to defrost the propellers, wing surfaces,4 tail'surfaces, etc. Y

Another object of thisA invention is to provide a, portable aircraft heater that is convenient and safe to employ, embodying a fully insulated re box, stack, etc., and embodying spark arrestors in the stack. v

Another object of this invention is to provide a portable aircraft heater that is self-contained or sloped rearwardly and upwardly and 2|! projects laterally from these cutaway parts of the body "sides Il.

and compact, including a fuel supply, a burner, 5

A further object of this invention is to provide an aircraft preheater that is inexpensive to manufacture and that is efficient and inexpensive in operation.

The various objects and features of my inven- "tion will be fully understood from the following detaileddescription'of atypical preferred form and `application of my invention, throughout which description reference is made tothe accompanying drawings, in which:

Fig;y 1 is a perspective view of the heater of the I present invention with its shroud in active position around the cowl of an aircraft engine. Fig. 2 is an enlarged vertical detailed sectional view of the principal portion of the heater showing a partvof the stack and the fuelsupplyvtank-in elevation. Fig. 3 is a fragmentary side elevation of the shroud. Fig. 4 is a rear elevation of the f shroud and Fig. 5 is an kenlarged fragmentary transverse detailed sectional view taken as 'indicated by line 5--5 on Fig.2'.

The improved portable aircraft heater of the invention may be said to comprise, generally, a

wheeled carrier or body l0, a iire box H on the body l0, a burner I2 at the're box Il, fuel supply means 3 carried by the body`lll for delivering fuel to the burner. I2, an adjustable heat delivering stack M for the re box ll and a shroud Id Afor communicating with the upper end of the stack It and adapted to t about a cowl 0.0i an engine.

The body l0 serves to support the various other parts of the device and in accordance with the invention is in the form of a vehicle or wheeled carrier so that the device may be readily moved about by the operator. The 'body I0 maybe varied considerably without ydeparting 'from the invention. In the case illustrated the body I0 has a bottom I6, spaced sides I1, a forward end I8, 'and' a rear end I9. The sides l1 and the front I8 are substantially upright. The rear portion of the bottom I6 curves upwardly and rearwardly so that it may have a sled or'skid action. The forward ends of the sides- I1 are cut back an axle Suitable wheels 2| are rotatable on the projecting parts of the axle 20 and may be provided with pneumatic tires. The intermediate portion 22 of the axle 20 is stepped` rearwardly to be some distance from the forward end of the body l0. Handles 23 are provided to facilitatethemanipulation and manual propulsion of the heater. The handles 23 project upwardly and rearwardly from` the rear portion of the body I and are joined between their ends by a brace 24. It is preferred to connect the handles 23 with the body sides I1 in such a manner that the handles may be folded or swung toretracted or inactive positions. Hinge pins 25 pivotally connect the lower ends of the handles 23 with the body sides I1 and pins 26 provided with removable wing nuts connect the handlesv with the body sides I1 at points spaced from the hinge pins 25 to normally hold the handles in their active positions. Suitable grips may be provided on the outer ends of the handles 23.

The combustion chamber or fire box II is arranged on the body I8 below the stack I4. The fire box I I includes a generally horizontal rear portion 21 and an upright portion 28 `ioining the horizontal portion 21. 'I'he rear portion 21 of the fire box Il is arranged longitudinally between the body sides I 1 and has an access opening in its upper end normally closed by a hinged or rey movable cover-29. The upright portion 28 of the fire box I I is supported by legs 30 suitably secured to the bottom IB'of the body I0. I'he upper part of the upright re box portion 28 may be reduced or tapered. 'I'he substantially horizontal fire box portion 21 discharges into the lower end of the upright box portion 28 and the heat rises through the portion 28 to pass upwardly into the stack I4. The fire box II may be suitably insulated.

The burner I2 is preferably arranged to direct its ame forwardly in the rear portion 21 of the flre box I I. Any suitable form or type of uid fuel burner may be employed. In the typical form of the invention illustrated the burner I2 is. a blow torch type of burner including a perforated flame tube 3|. The torch tube 3|' is supported in the rear portionof the flre box II to direct its flame forwardly through the fire box portion 21. The burner I2 may be suitably attached to the rear end I9 of the 'body I8. The burner I2 preferably includes a control valve 32 accessible at the rear of the body- I0. The burner I2 is accessible through the access opening of the box portion 21 to be readily lit, examined, cleaned, etc.

. 48 to better It is a feature of the invention that the fuel 4 supply means I3 is carried by the mobile body I0 to make the heater self-contained and fully portable, The fuel supply means I3 includes a container or tank 33 for holding a suitable fuel. The fuel employed may be propane or butane held under a suitable pressure. The fuel tank 33 is arranged in front Iof the nre box II and its lower end may rest on the bottom I6 of the body IIJ. Tme bent axle portion 22 forms a yoke for engaging about the rear of the tank 33 and the body front I8 may be shaped to iit about the tank. An upwardly projecting standard 34 is provided at the rear of the tank 33 and carries a yoke or fork 35 for engaging about the rear of the tank 33 adjacent the upper end of the tank. A chain v36 is releasably secured to the arms of the fork 35 and engages about the tank 33 to hold the tank in place. A fitting 31 is secured to the upper end of the tank 33 and has an appropriate valve 38 and a pressure gauge 39. A uid line or pipe 43 leads from the valved fitting 31 to the valve 32 of the burnerv I2. An insulated partition 40 may I8 at the front of the re be secured in the body box Il to protect the tank 33 against excessive heat. Means is provided for heating the fuel tank 33 in very cold weather. An opening 4I is formed in the forward wall of the rear side of the tank 33. A hinged or swinging cover 42 normally closes the opening 4I. When the opening 4I is uncovered heat from the re box II rises about the tank 33`to warm the same. The fuel tank 33 arranged as described above may be removed for replacement when empty. 'I'he pipe 42 is readily disconnected from the tting 31 and the chain 38 is easily released to free the tank 33 for removal.

'I'he heating flue or stack I4 carries the heat upwardly for delivery to the shroud I5 or for direct delivery to compartments of the aircraft. accordance with the invention the stack I4 is adjustable. comprising a stationary section 44 and an adjustable or shiftable section 45. The relatively stationary stack section 44 is secured to a reduced neck 48 on the upper end of the re box II and extends upwardly a substantial distance. vIt is preferred to insulate the lower stack section 44. In practice the stack section 44 may be constructed of two spaced concentric tubes with a suitable insulating material 44l packed between the tubes. Vertically spaced spark arrestors 41 are secured in the stack section 44. The spark arrestors 41 are preferably in the nature of wire mesh screens and prevent the passage of sparks into the upper stack section 45 and the shroud I5.

The shiftable stack section 45 extends downwardly over the relatively stationary section 44. 'I'he stack section 45 is a rigid metal tube and surrounds the section 44 with substantial clearance leaving an annular air passage 48. 'I'he passage 48 serves to admit air to the column of heated air passing through the stack I4. The lower end of the stack section 45 is ared as at heat or heated air passing upwardly through the 'stack I4 draws or induces outside air through the opening 48. Spaced vertically extending ribs R are secured to the interior of the stack section 45 and engage or ride on the stack section 44 to maintain the spaced relation of the stack sections 44 and 45. Means is provided for releasably holding or supporting the shiftable stack section 45 at any lselected or required elevation.

'I'his means comprises a strip or plate 50 arranged longitudinally of and secured to the stack section 44. The plate 50 of spaced openings 5I. A shiftable pin or latch 52 is carried by the stack section 45 to cooperate the-fire box II to oppose with the openings 5I. The latch 52 passes f hrough openings inthe section 45 and a housing 53 secured to the exterior of the stack section. A compression spring 54 is arranged in the housing 53 to bear inwardly against a collar 55 flxed to the latch 52. The outer end of the latch 52 has a suitable handle 56. The latch 52 may be released by pulling outwardly on the handle 56 and may be engaged in any selected opening 5I to retain or support the stackV section 45 in the selected position.

The shroud I5 is adapted to be arranged about the cowl of the engine to beheated and, of course, may be lvaried in size, shape and construction to adapt it for application `to different types of engines. In the case illustrated the shroud I5 is shaped to t about a substantially cylindrical engine cowl C having a rounded forward end. The shroud I5 is preferably formed of fabric which may be treated to be heat and lire resisting or is formed of asbestos fabric and is shaped to readily fit about the cowl C. A central opening 51 is provided in the forward end of the shroud I5 admit the air to the opening 48. 'I'he l is provided with a row ler 59. A slit 60 extends from the opening 51 to the rear end of the shroud I5. 'Releasable fasteners 6I, such as snap fastenersare arranged along the margins of the slit 68 and are adapted to close the slit to hold the shroud AI about the cowl C. A draw cord 63 may be laced through a doubled rear edge portion of the shroud I5 to assist in retaining the shroud on the cowl C. Ihe draw cord 63 may have protruding ed to be tensioned to' draw the cord tightly on the cowl C and adapted to be tied.

An adjustable and readily disconnectable means is provided for associating the shroud I5 with the stack I4. This means includes a segmental or partially circular plate 64 of substantially rigid material secured to t'ne front of the shroud I5. The plate 64 is below the'opening 51 and covers a substantial part of the shrouds front. An opening 65 is provided in the plate 64 and is located at one side of the opening 51.' A tube or pipe 66 is secured in the opening 65 vand extends downwardly and outwardly from the plate'64. AAn adjustable elbow 61 is secured to the lower end of the pipe 66. A flexible pipe or tube 68 is secured to the elbow 61 by a 'securing band 69 and hangslfrom the elbow. The tube 68 is formed of asbestos fabric or the like to be re and heat resistant. 'Ihe flexible tube 68 is of substantial length and isl proportioned to be passed down over the section 45 of the stack I4. A exible band 10 is provided on the lower end of the flexible tube 68 and may be tightened to draw the tube 68 onto the stack section 45. With the tube 68 engaged over the stack section 45 the interior of the shroud I5 is in communication with the heater stack I4 to receive the heat therefrom. A deiiector 12 may be secured in the opening 65 or the upper portion of the pipe 66. The deiiector 12 may comprise a series of spaced vanes arranged to direct the heated air so that it takes a circular path in the shroud.

In the use or operation of the heater the shroud I5 is initially or normally disconnected from the stack I4. The heater may be readily moved or wheeled about and brought to a position .adjacent the aircraft. If desired, the stack section 45 may be adjusted vertically and brought to a position to have its upper end discharge directly into a compartment of the aircraft such as the passenger compartment, the nacelles, or the like. In this connection it will be observed that the stack section 45 may bereadily adjusted vertically and releasably secured in the adjusted position by means of the latch 52. The heater I2 may be ignited and controlled by the valves 88 and 82 to provide the necessary heat. The burner I2 directs its 'flame substantially horizontally in the fire box portion 28 and the heat 'of the name rises through the fire box portion 28 and the stack I4.

. The rising heat induces or draws air through the passage 48 and this air is warmedor heated as it continues through the stack. heater warmsethe compartment In practice the of the aircraft in end portions adapt a mosty eifective manner. Practically all the heat generated by the burner I2 is delivered to the alrplane compartment and there is little or no heat loss and the heating operation requires a minimum of time.

When it is desired to warm or preheat an aircraft engine the heater is brought to 'a convenient position adjacent the engine. The shroud I5 is wrapped about or arranged over the aircraft engine cowl C and secured in place by means of draw cord 63. The flexthe fasteners 6I and the ible tube 68 is then passed over the upper portion of the stack section 65. The elbow 61 may be adjusted to bring the tube 68 into alignment with the stack I4 and the stack section 45 may be adjusted vertically to extend a suitable distance into the iiexlble tube 60. The heat from the burner I2 passes up the stack I4 and the tube 68 to be delivered to the shroud I5. Air is induced through the passage 48and is warmed as it ows upwardly in the stack I4 and tube 68. The shroud' l5 may completely enclose the engine containing portion i cally all of the heat is delivered to the engine. The heater of the invention is operable to evenly and thoroughly heat the engine in a minimum of time, The engine may be brought to a temperature at which it will operate most eiciently. The shroud I5 may be quickly removed from about the cowl C and the portable heater may be moved away from the aircraft.

Having described only a typical preferred form and application of the invention,.I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modications that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

1. A device for heating aircraft engines, compartments,etc. including a body, a re box on the body having an upwardly extending heat passing stack, burner means `at the nre box, a fuel container supported by the body to be in adjacent relation to the nre box, means for conducting fuel from the container to the burner means,

.the nre box having an opening for passing heat to the container to preheat the fuel therein, and means controlling said opening.

2. A device for heating aircraft engines, com- Y partments, etc. including a fire box, an upwardly extending heat conducting stack leading from the tire box, the stack ary stack section on the fire box, a shiftable stack section telescoping over the upper portion of the rst named stack section with clearance, leaving a passage through which air is induced into the stack, and means guiding the second mentioned l stack section for vertical adjustment, and burner means at the fire box.

JAME/T. KING.

of the cowl C so that practiy including a relatively station- 

